Bilirubin test material

ABSTRACT

A diagnostic test indicator for the detection and determination of the concentration of bilirubin in sera comprising a bibulous material, which has contained therein the dried residue resulting from the impregnation thereof with 1. MALEIC ACID, 2. STARCH AND 3. A DIAZONIUM SALT, AND A PROCESS FOR THE PRODUCTION OF SAID INDICATOR, ARE DISCLOSED.

United States Patent [1 1 Forgione [4 1 Oct. 28, 1975 BILIRUBIN TEST MATERIAL [73] Assignee: American Cyanamid Company,

Stamford, Conn.

[22] Filed: Aug. 14, 1974 [2]] Appl. No.1 497,438

[56] References Cited UNITED STATES PATENTS 5/1970 Green 23/230 B 6/1974 Fraser, Jr. et a1. 23/230 B 7/1974 Morin 23/230 B 12/1974 Rittersdorf et a1 23/253 TP Primary Examiner-R. E. Serwin Attorney, Agent, or FirmFrank M. Van Riet [5 7] ABSTRACT A diagnostic test indicator for the detection and determination of the concentration of bilirubin in sera comprising a bibulous material, which has contained therein the dried residue resulting from the impregnation thereof with 1. maleic acid,

2. starch and 3. a diazonium salt, and a process for the production of said indicator, are disclosed.

13 Claims, No Drawings BILIRUBIN TEST MATERIAL BACKGROUND OF THE INVENTION The use of diagnostic tests in the clinical testing of patients has become increasingly common in recent years. Many of these tests employ the use of test papers wherein the individual conducting the test merely contacts a reactive paper strip with a suspect material, usually a body fluid, and observes the color change or color intensity thereof in order to determine whether or not a particular effect is achieved. Test strips or cards of this type have been devised for glucose determinationand treponemal diseases, for example.

Most tests for the detection of the concentration of bilirubin in body fluids have, until now, consisted of intricate liquid or tablet systems whereby accelerators such as caffiene, acetamide, etc. must be employed. There has therefore existed, for a substantial period of time, the need for a simple testing mechanism for the determination of the concentration of bilirubin in sera, which long-felt need is satisfied by the instant invention, more fully discussed hereinbelow.

SUMMARY As mentioned briefly above, I have now discovered a novel test means for the determination of the concentration of bilirubin in body fluids without the use of instrumentation. My test means is useful for the qualitative detection and quantitative determination of bilirubin wherein the test means comprises a reagent composition incorporated within a bibulous carrier and ex cludes the need for extraneous accelerators.

The quantitative determination of bilirubin is extremely important in the detection of bilirubin liver diseases, in that the concentration of bilirubin in the blood is elevated noticeably over its normal concentration when diseases of the liver exist. The early detection of such an abnormal rise in bilirubin concentration can therefore obviously lead to a more accurate and rapid diagnosis of liver maladies and consequently, the more rapid treatment thereof.

Because early diagnosis of abnormal liver conditions is so important, a test for the detection of variables in the concentration of bilirubin in the blood must not only be rapid and simple enough for the clinician to carry out but accurate enough to enable the diagnosis to be made without extreme chances of error or false readings. Such a mechanism is represented by the novel test indicators of the present invention. Utilizing my novel system, no instrumentation is necessary and no mixing or reconstitution of reagents is needed. Testing can therefore be conducted at home or in the doctors office without any special equipment.

Although many tests useful in the detection of bilirubin have been known e.g. see US. Pat. No. 3,585,004, British Pat. Specification No. 1,330,094, Clinica Chemica Octa, Columbo et al, Vol. 51, pages 217--2l9,

about three minutes. The unique combination of ingredients used enables the instant indicators to be of higher sensitivity and larger shelf life than existing systems.

DESCRIPTION OF THE INVENTION INCLUDING PREFERRED EMBODIMENTS My novel diagnostic test indicators for the determination of the concentration of bilirubin comprise a bibulous carrier material, such as cellulosic paper, which contains therein the dried residue resulting from the impregnation thereof with various reagent materials.

In the preparation of my novel indicators, the solution with which the bibulous material is to be impregnated is prepared by first forming an aqueous solution of starch. The starch functions as a stabilizer for the diazonium salt indicator and is preferably added to the impregnating solution first, however, itmay be added to the impregnating solution last or at any other time during the solution preparation. The starch is employed in stabilizing concentrations, i.e., those ranging from about 1.0% to about 5.0%, preferably from about 3.0% to about 4.0%, (W/V). The starch enables the resultant test indicators of this invention to be stored without deterioration, especially at 10C. and preferably over a drying agent.

To the starch containing impregnating solution is then added the maleic acid in a concentration ranging from about 5.0% to about 30.0%, preferably from about 10.0% to about 22.0%, (W/V) to maintain the pH of the impregnating solution on the acid side, i.e., about 1.7-2.9.

The diazonium salt is then added to the resultant impregnating solution in concentrations ranging from about 0.1% to about 2.0%, |(W/V) preferably from about 0.5% to about 1.0%. This material is capable of imparting to the area of the bibulous material which comes into contact with the sera, a color of such varying intensity as to be representative of the concentration of the bilirubin which is present therein. The diazonium salts per se are well known in the art and generally have the formula wherein R R and R are, individually, H, N0 CH OCl-I C1 or NHCOC I-I and X is C1, or B1 The indicator is then prepared by dipping the bibulous material in the resultant impregnating solution, recovering the so impregnated material and drying. Although the above method of impregnating the bibulous material is preferred, it is also possible to impregnate the material with individual solutions of the ingredients with drying of the bibulous material between each impregnation.

It can therefore be seen that once the sera is added to the test indicator, the bilirubin therein causes a reaction which eventually results in the coupling of the diazonium salt, i.e., the formation of a colored indicator,

5 the intensity of which is directly proportional to the The impregnation time of the impregnations, either concentration of the bilirubin in the sera. The clinician individual or combined, discussed above, is not critical merely Compares the hi @sults a f as long as the bibulous material is fully saturated by the color chart to ascertain the bilirubin concentration in solution with which it is contacted. Generally, submerthe Serum bemg testedsion of the bibulous material in the solution for from The indicators of the Present invention generally about 5 to minutes is ffi i in most eases hibit various intensities of red which are indicative of high bilirubin levels in the test sera to yellow which indicates a normal bilirubin level.

After the Starch adeed to the water e suspehslon The above concentrations expressed in connection is preferably warmed in order to effect dissolution of 15 With the Components Which may be incorporated into the e e Hot water can also be used" The ,resul'faht my novel indicators are set forth as to the solution of soluheh 15 then preferably eeeled before the dlazemum these components which is saturated onto the bibulous salt is added thereto. If desired, of course, the starch carrier only and is not meant to Specify the amount of sohmon or e malelc e h be adeed to a each component which is eventually present on the bibprepared Soluheh of the dlazomum h 1h e a 2O ulous carrier. That is to say, saturation of the bibulous eentrat'on .that the h e starch melele h e e Salt carrier with a specific concentration of a specific comconcentrations fall within the abovespecified limits. ponent in sohition will not uivocally incorporate into the bibulous carrier the same amount or percent- The pH f the impregnated bibulous test indieator age of component present in the solution. I have found should range fret about t0 about 29, in Order f however, that the above concentrations of components the indicator to function at the optimal reactivity of the in Solution are hy sufhcieht so as to h 'p diazonium salt. The depth or intensity of color and re- Sufficieht component Into the blbulous matehal p activity is materially reduced at outside f this saturation therewith to produce a functional test indirange cator, the absorptive capabilities of the bibulous material being characteristic of materials generally used for this purpose.

Order to ohtalh the most uhlformly lmpl'eghated The following examples are set forth for purposes of hlhhlous mammal and thereby the most accurate test illustration only and are not to be construed as limitaindicator, I have found it advantageous, but not critical, tiohs on the presetit ihvehtion except as set f h in the to use a suitable non-ionic wetting agent in the impregappended Claims. A11 pat-ts and percentages are by nating solution so as to assure complete coverage of the Weight unless otherwise specified surface of the bibulous materials when contacting them with the solution. For instance I may utilize the fatty al- EXAMPLE 1 kanolamides, i.e., reaction products of an alkanolamine 40 A 30% starch sohition is prepared by slowly adding, Wlth 3 h Such as launc ac ld or str'lppedfocohut with stirring, 3.0 parts of soluble starch to 100 parts of fatty smtable an{molammeshemg dlethahol' boiling water. The resultant solution is then cooled to amme mohoethaholamfhes mohhlsopfopaholammei room temperature and the following components are e ethylene exlde hem/ed matenals these added in the order specified: 1 1.0 parts of maleic acid, rived from the reaction of ethylene oxide with alkyl- 02 parts of a 10% aqueous solution of polyethylene Phenols the alkyl group 15 eetyh hohyl or (23) lauryl ether and 0.5 part of p-nitrobenzene diazohigher, long Chi-1111. fatty alcohols such as t 'idecyl alconium fluoroborata The pH is 24 alcohol e" h h h aelds A commercially available Whatman No. 3 cellulosic such as lemme aeld tall elele held ebletlc aeld e paper is dipped into the resultant solution for 7 minutes long chain fatty mercaptans, long chain fatty amines, and is then dried polyofypropylene glycolifatty sofbitan ester; sugar A drop of suspect serum is then added to the test ters, i.e., the alcoholysis reaction products of the paper and is allowed to set for 3 minutes. The test methyl ester of a fatty acid e Sucrose or raffinose; paper turns violet red indicating an abnormal concenpolysorbltol; methyl cellulose ethoxylated phenol/for tration of bilirubin. Control serum containing a normal maldehyde resms and the polyoxyethyleneelong bilirubin concentration turns the test a er ellow chain fatty acid ethers are preferred. Amounts ranging p p y from about 0.01 part to 1.0 part of wetting agent per EXAMPLE 2 100 parts of solunon may be used' The procedure of Example 1 is again followed except that the diazonium salt used is that corresponding to The mechanism by which the instant test indicators Formula I, above, wherein R, is Z-methoxy, R is 4- function, although not wishing to be bound by any cx- NHCOC I-I R is S-methyl and X is Cl. Similar repressed theory, is believed to occur thusly: sults are achieved.

CH ciiciizcooR' i CH\3 C 2 Bilirnbin RN lp /k i i Salt so N g N=NR glucur'onyl EXAMPLE 3 The procedure of Example 1 is again followed except that the polyethylene (23) lauryl ether is omitted and the paper is dipped into the solution for minutes. Substantially identical results are observed.

EXAMPLE 4 Example 1 is again followed except that the bibulous material is Whatman No. 42 cellulosic paper. Again, a deep red spot appears on the resultant indicator when an abnormally high bilirubin concentration is present in the test serum.

1 claim:

1. A diagnostic test indicator for the detection and concentration determination of bilirubin in sera comprising a bibulous material which contains therein, at a pH of from about 1.7 to about 2.9, the dried residue resulting from the impregnation thereof with l. maleic acid 2. starch and 3. a diazonium salt.

2. A diagnostic test indicator according to claim 1 wherein said (3) is a 2-methoxy-4-benzamido-5-methyl diazonium salt.

3. A diagnostic test indicator according to claim 1 wherein said (3) is p-nitrobenzene diazonium fluoroborate.

4. A diagnostic test indicator according to claim 1 wherein said bibulous material is paper.

5. A process for the preparation of the diagnostic test indicator of claim 1 which comprises impregnating a bibulous material with an aqueous solution of said l (2) and (3) and thereafter drying the thus impregnated material.

6. A process according to claim 5 wherein said (3) is 2-methoxy-4-benzamido-5-methyl diazonium chloride.

7. A process according to claim 5 wherein said solution of l (2) and (3) is at a pH offrom about 1.7 to about 2.9.

8. A process according to claim 5 wherein said (3) is p-nitrobenzene diazonium fluoroborate.

9. A process according to claim 5 wherein said bibulous material is paper.

10. A diagnostic test indicator according to claim 1 which contains (4) a wetting; agent.

11. A diagnostic test indicator according to claim 10 wherein said (4) is polyethylene lauryl ether.

12. A process according to claim 5 wherein said solution includes (4) a wetting agent.

13. A process according to claim 12 wherein said (4) is polyethylene lauryl ether. 

1. A DIAGONASTIC TEST INDICATOR FOR THE DIRECTION AND CONCENTRATION DETERMINATION OF BILIRUBIN IN SERA COMPRISING A BIBULOUS MATERIAL WHICH CONTAINS THEREIN, AT A PH FROM ABOUT 1.7 TO ABOUT 2.9, THE DRIED RESIDUE FROM THE IMPREGNATION THEREOF WITH
 1. MALEIC ACID
 2. STARCH AND
 2. starch and
 2. A diagnostic test indicator according to claim 1 wherein said (3) is a 2-methoxy-4-benzamido-5-methyl diazonium salt.
 3. A diagnostic test indicator according to claim 1 wherein said (3) is p-nitrobenzene diazonium fluoroborate.
 3. a diazonium salt.
 3. A DIAZONIUM SALT.
 4. A diagnostic test indicator according to claim 1 wherein said bibulous material is paper.
 5. A process for the preparation of the diagnostic test indicator of claim 1 which comprises impregnating a bibulous material with an aqueous solution of said (1), (2) and (3) and thereafter drying the thus impregnated material.
 6. A process according to claim 5 wherein said (3) is 2-methoxy-4-benzamido-5-methyl diazonium chloride.
 7. A process according to claim 5 wherein said solution of (1), (2) and (3) is at a pH of from about 1.7 to about 2.9.
 8. A process according to claim 5 wherein said (3) is p-nitrobenzene diazonium fluoroborate.
 9. A process according to claim 5 wherein said bibulous material is paper.
 10. A diagnostic test indicator according to claim 1 which contains (4) a wetting agent.
 11. A diagnostic test indicator according to claim 10 wherein said (4) is polyethylene lauryl ether.
 12. A process according to claim 5 wherein said solution includes (4) a wetting agent.
 13. A process according to claim 12 wherein said (4) is polyethylene lauryl ether. 